The paper presents an offline method to reduce the dimension of design spaces in hydrodynamic shape optimization. The geometry based method (developed by the authors in earlier research) is extended, bringing physics based information into the design variability analysis. The generalized Karhunen-Lo` ve expansion is applied to a combined geometry and physics based design modification vector, embedded in a generalized (disjoint) Hilbert space. Design spaces are assessed in terms of Karhunen-Loève modes (eigenvectors) and associated variance (eigenvalues). The former are used as a basis to build a reduced-dimensionality representation of the shape modification, retaining the 95% of the original design variability. The method is demonstrated for the design-space dimensionality reduction of the DTMB 5415 bare hull. The dimensionality reduction is based on geometry, wave resistance coefficient, pressure distribution, and wave elevation at Fr = 0.25, evaluated by linear potential flow theory. Compared to the geometry based method, the current extension to combined geometry and physics based analysis improves the effectiveness of the design-space dimensionality reduction.
Combined Geometry and Physics Based Method for Design-space Dimensionality Reduction in Hydrodynamic Shape Optimization
Diez;Matteo;Serani;Andrea;Campana;Emilio Fortunato
2016
Abstract
The paper presents an offline method to reduce the dimension of design spaces in hydrodynamic shape optimization. The geometry based method (developed by the authors in earlier research) is extended, bringing physics based information into the design variability analysis. The generalized Karhunen-Lo` ve expansion is applied to a combined geometry and physics based design modification vector, embedded in a generalized (disjoint) Hilbert space. Design spaces are assessed in terms of Karhunen-Loève modes (eigenvectors) and associated variance (eigenvalues). The former are used as a basis to build a reduced-dimensionality representation of the shape modification, retaining the 95% of the original design variability. The method is demonstrated for the design-space dimensionality reduction of the DTMB 5415 bare hull. The dimensionality reduction is based on geometry, wave resistance coefficient, pressure distribution, and wave elevation at Fr = 0.25, evaluated by linear potential flow theory. Compared to the geometry based method, the current extension to combined geometry and physics based analysis improves the effectiveness of the design-space dimensionality reduction.File | Dimensione | Formato | |
---|---|---|---|
prod_370511-doc_123763.pdf
solo utenti autorizzati
Descrizione: Combined Geometry and Physics Based Method for Design-space Dimensionality Reduction in Hydrodynamic Shape Optimization
Tipologia:
Versione Editoriale (PDF)
Licenza:
Dominio pubblico
Dimensione
9.62 MB
Formato
Adobe PDF
|
9.62 MB | Adobe PDF | Visualizza/Apri Richiedi una copia |
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.